Writing instrument



FIG. 1 is a left side elevational view of a writing instrument showing my new design;

FIG. 2 is a top plan view;

FIG. 3 is a bottom plan view;

FIG. 4 is a front elevational view;

FIG. 5 is a right side elevational view; and,

FIG. 6 is a perspective view thereof.

The writing instrument tip depicted by means of broken lines in FIGS. 1 and 3 through 6 has been shown for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a writing instrument, as shown and described. 